Device in a type printer

ABSTRACT

A motion mechanism in a type printer, wherein the axial displacement of a type drum relative to a printing hammer for setting the required type in position opposite the hammer, and the axial movement of both hammer and type drum for obtaining a new printing position on the sheet, is effected by means of a cord system which consists of a single cord, a type of endless chain. The cord runs over pulleys arranged at each end of the line to be printed, such that the cord is divided into four cord parts extending substantially parallel to the line on the sheet, one cord part supporting the hammer, and one supporting the type drum. At one side, two pulleys are arranged in spaced relationship on a plate which is mounted pivotally about an axis lying intermediate the rotational axes for the two pulleys. Furthermore the cord co-operates with a driving motor operating on that part of the cord which leads to the hammer. Setting of the hammer to a new printing position on the sheet is then effected by displacing the whole cord in its length direcion by means of the driving motor, whereby the hammer and the type drum will move equal distances. Setting of the type drum to a posion with a new type opposite the hammer is made by pivoting the mounting plate for the pulleys, whereby the type drum only is moved, while the hammer is held fixed.

United States Patent [191 Ulin [4 1 Apr. 16, 1974 1 DEVICE IN A TYPEPRINTER 22 Filed: Aug. filo, 1972 [2]] Appl. No.2 284,959

[30] Foreign Application Priority Data Aug. 31, 1971 Sweden 11034/71[52] US. Cl. 197/49 [51] Int. Cl B4lj l/32 [58] Field of Search 197/49,16, l B, 55; 101/93 C [56] References Cited.

UNITED STATES PATENTS 3,374,873 3/1968 Takenaka 197/49 3,696,204 10/1972Wallskog 197/49 X 2,757,775 8/1956 l-lickerson... 197/49 3,422,9451/1969 Bethune 197/49 X 3,042,174 7/1962 Howard 197/49 X l/l966 Howard107/49 Primary Examiner-Robert E. P ulfrey Assistant Examiner-R. T.Rader Attorney, Agent, or Firm-Frank R. Trifari [5 7] ABSTRACT A motionmechanism in a type printer, wherein the axial displacement of a typedrum relative to a printing hammer for setting the required type inposition opposite the hammer, and the axial movement of both hammer andtype drum for obtaining a new printing position on the sheet, iseffected by means of a cord system which consists of a single cord, atype of endless chain. The cord runs over pulleys arranged at each endof the line to be printed, such that the cord is divided into four cordparts extending substantially parallel to the line on the sheet, onecord part supporting the hammer, and one supporting the type drum. Atone side, two pulleys are arranged in spaced relationship on a platewhich is mounted pivotally about an axis lying intermediate therotational axes for the two pulleys. Furthermore the cord co-operateswith a driving motor operating on that part of the cord which leads tothe hammer. Setting of the hammer to a new printing position on thesheet is then effected by displacing the whole cord in its lengthdirecion by means of the driving motor, whereby the hammer and the typedrum will move equal distances. Setting of the type drum to a posionwith a new type opposite the hammer is made by pivoting the mountingplate for the pulleys, whereby the type drum only is moved, while thehammer is held fixed.

3 Claims, 3 Drawing Figures 1 DEVICE IN A TYPE PRINTER The inventionrelates to a device in a printer comprising a type drum with typesarranged around the periphery. The drum is mounted in two waysrotatably, and;

axially displaceable for setting required type opposite a hammer unit.The hammer which is pressed against the drum with an interposed printingsheet produces printing on the sheet displacement of the drum and thehammer unit for setting the hammer in desired printing position alongthe line on the sheet to be printed, and displacement of the drumrelative to the hammer for the axial setting of the drum are achieved bymeans of a cord system comprising a first cord part supporting thehammer unit, and a second cord part supporting the drum and cooperatingwith pulleys and driving means, which cord parts extend along the lineto be printed.

Known devices of this kind have a complicated cord system with separatecords for the type drum andthe hammer unit, respectively. The cords forchanging the printing position are driven in parallel, while for theaxial displacement of the type drum only one of the cords is actuated.

The invention has for its object, in such a device, to produce. asimplification of the cord system and a decreaseof the required inertiaof the movable parts, thereby enabling higher printing speed. Thecharacteristic for the invention consists in that one end of the firstcord part is, via'a return cord, directly connected with'the oppositeend of the second cord part. This part in corresponding manner, is via areturn cord directly connected with the opposite end of the first cordpart. This forms a continuous cord system a type of endless chain,which'supports both the hammer unit and the type drum. At one end ofthis system, the pulleys, where the respective cord part is continuousin the return cord, are arranged at a distance from each other on amounting plate which is swingable about an axis extending substantiallyparallel to the rotational 'axes for the pulleys, and is situatedhalf-way between the rotational axes for the pulleys. A change ofprinting position is produced by displacement of the whole cordsystem inthe length direction of thecord which conforms both the hammer unit andthe typedrum to follow this motion, while axial displacement of the drumrelative to the hammer, is produced by pivoting the mounting plate whilelocking'the. cord part which supports the hammer unit.

In a device according to the invention, the cord system consists of onesingle, continuous cord, a type of endless chain, comprising only fourcord parts extending parallel with the line to be printed, two of thecord parts serving to support the hammer unit and the type drum,respectively, and two return cords. Change of the printing position isproduced simply by movingthecord in its length direction, whereby boththe hammer unit and the drum will be forced to move an equal distance.Change of the position of the type drum relative. to the hammer unit, isproduced by influencing the mounting plate for the two pivotably mountedpulleys. Thesepulleys can be arranged relatively close to each other,and the mounting plate with pulleys will then have small dimensionsresulting in a small inertia mass and short setting time. Suitablestepping motors can be used for both motions, which will give exactlyadapted driving steps and automatic locking of the respective drivingwheel during intervals between the stepping operation.

The invention is illustrated in the accompanying drawings, in which;

FIGS. 1 and 2 show two schematic views of the cord system in a deviceaccording to the invention, and

FIG. 3 shows a perspective view of a complete type printer provided witha device according to the invention.

The principle for driving the hammer unit and the type drum in a drivingsystem according to the invention is evident from FIG. 1, in which thehammer unit is designated 10 and the type drum is designated 11. Aprinting sheet is schematically indicated at 12. The hammer unit isfastened to a first cord part 13 extending between a driving wheel 14situated on one side of the printing sheet, and'a pulley l5 situated atthe opposite side of the printing sheet. From the pulley 15, the cordruns via a cord part 16, to a pulley l7 situated on the same side of theprinting sheet as the driving wheel 14. From the last pulley 17, thecord continues via cord part 18, to a further pulley 19 situated at theopposite side of the printing sheet. This cord part 18 supports the typedrum 11. From the pulley 19, the cord finally runs through a cord part20 back to the driving wheel 14.. The end portions of the cord are wounda number of turns upon the wheel 14 and frictionally engage to thewheel, whereby the cord will follow the wheel when it is rotated. Thedriving wheel 14 andthe pulley 17 are mounted on fixed shafts, while thepulleys 15, 19 situated at the opposite. side of the sheet are mountedon amounting plate 21, which is pivotable about an axis 0. The axis 0 islocated half-way between the rotational axes for the two pulleys 15, and19. When the plate is swung about 0, one of the pulleys will approachthe printing position a distance equal to the distance the second pulleywill move away from the position pivoting of the plate about 0 whileclamping those cord parts which run to the driving wheel 14, will herebybe possible. The motion of the plate 21 is controlled by a driving wheel22 cooperating with a toothed segment 23 situated at one side of theplate. It is evident that, if the driving wheel14 is rotated, the hammerunit 10 and the type drum 11 will be displaced equal distances. Thehammer unit 10 deter mines the printing position and setting of thewheel 14 and changes the printing position on the printing sheet.Because rotation of the wheel 14 displaces the type drum an equaldistance as that of the hammer unit, the mutual position between thehammer and the type drum will not be changed. 0n the contrary, if thewheel 14 is kept fixed, and the mounting plate 21 is pivoted about axis0, the hammer unit 10 will remain in its position because it is directlyconnected with the locked driving wheel 14, while the type drum 11 isdisplaced v relative to the hammer unit. Pivoting the plate 21 istherefore made for setting the desired type column on the drum 11opposite the hammer 10.

In FIG. 2, where corresponding parts have been provided with the samereference numerals as inFlG. 1, an alternative embodiment of the deviceaccording to FIG. 1 is shown. The device according to FIG. 2 isdifferent from that of FIG. 1: only in a slightly different cordarrangement, and in the replacement of pulley 17 (FIG. 1) with twopulleys 24, 25. The arrangement according to FIG. 2 is better inachieving a desired mutual placing of the type drum and the hammer unit.The

hammer unit in FIG. 2 is as in FIG. 1 arranged on a cord part leadingdirectly to the drive wheel 14. This wheel determines the position ofthe hammer unit, and thereby controls the printing position, while theposition of the drum relative to the hammer unit is determined by thesetting angle of the mounting plate 21.

FIG. 3 shows a perspective view of a complete printer constructed inaccordance with the principle shown in FIG. 2. In FIG. 3 the followingparts can be recognized: the hammer unit 10, the type drum 11, the cordparts 13, 16, 18, and 20, the driving wheel 14 and the pulleys 24, andand 15 and 19. Pulleys 15 and 19 are arranged on the pivotable mountingplate 21. The driving wheel 14 is arranged on the output shaft of afirst stepping motor 30, and the driving wheel 22, which is inengagement with the toothed segment 23 on the mounting plate 21, isconnected to the output shaft of a second stepping motor 31. Thestepping motor determines the position of the printing hammer, andthereby the printing position, while the stepping motor 31 determinesthe axial position of the type drum relative to the hammer. The typedrum 11 is displaceably arranged on a shaft 32 to which it is angularlylocked. The shaft 32 is coupled to a third stepping motor 33, whichdetermines the angular setting of the drum about its rotational axis. Bymeans of the stepping motors 31 and 33, the desired type is set oppositethe printing hammer.

The motion of the hammer for effecting printing is derived from acontinuously rotating motor 35, on the output shaft of which a cam disk36 is fixedly mounted. The cam disk 36 cooperates with a cam followerroll 37 mounted on an actuation arm 39, which arm projects from anactuating bar 38.

The actuating bar 38 is pivotally mounted and provided with an actuatingshoulder 40, which cooperates with the movably mounted hammer 41. Underthe influence of the motor 35, the bar 38 is acted upon in such mannerthat the shoulder 40 moves back and forth in a direction (shown by thearrows) axial to the hammer unit. In a rest position of the hammer unit,the hammer 41 is free from the shoulder 40 and no printing is effected.When order for printing is obtained, a mag net 42 is excited whichinfluences an armature 43. This armature is connected by a bar 44 to thehammer unit. Upon excitation of the magnet 42, the hammer unit isrotated in such manner that the hammer 41 comes into engagement with theshoulder 40 on the actuating bar 38. When the said shoulder next timemoves in a direction to the hammer, this hammer will be pressed againstthe drum 1 1, and printing will be effected. Finally there is also astepping motor 46 for driving the paper sheet l2, whichis unwound from astoring roll 47.

In operation the stepping motor 30 is first stepped forward a step tothe next printing position. Thereafter, or simultaneously therewith therequired type is set in position opposite the hammer by suitableexcitation of the stepping motors 31 and 33. After the setting order isaccomplished, magnet 42 is excited, and in described manner causesprinting to take place.

What is claimed is:

l. A printing apparatus, comprising:

a type drum having types arranged around a periphery thereof, said typedrum mounted for both axial displacement and rotation;

a printing hammer means movably disposed opposite said type drum, aprinting sheet passing therebetween; and

a cord for displacing said drum and said printing hammer means so thatthe hammer means is set in a desired printing position along a printingline of the printing sheet, and the drum is displaced relative to thehammer means, said cord having a first portion supporting the hammermeans, a second portion supporting said drum, said first and secondportions extending along a printing line of said printing sheet, a thirdcord portion extending between one end of said first portion and a firstend of said second portion, and a fourth portion ex- I tending betweenthe other ends of said first and second portions so as to form acontinuous cord system,

a driving wheel engaging said cord and disposed on one end of said cordsystem for moving said cord; and

a pair of pulleys disposed on another end of said cord system andengaging ,said cord, said pulleys being pivotably supported with respectto each and having a common pivotable axis between them, saiddisplacement of the drum relative to said hammer being achieved bypivoting said pulleys while locking the first cord portion supportingthe hammer means against movement.

2. The printing apparatus of claim 1, wherein said driving wheel ispowered by a stepping motor, and said first portion of the cordsupporting said hammer means extends from one of the pair of pulleys tosaid driving wheel.

3. The printing apparatus of claim 1, wherein said pair of pulleys aresupported upon a pivotable support member, said pivotable support memberbeing pivota bly driven by a stepping motor which is geared to saidsupport.

323323 I ED TATES PATENT OFFICE CERTIFICATE OF CQRRECTION ril 16, 1974Patent No. 225 Dated Inventofls) arl-Otto Ulin It is certified, thaterror appears in the above-identified patent v and that said LettersPatent are hereby corrected as shown below:

n the Title Page, after [76] Inventor: Carl-Otto Ulin, ack, 17500,

Jakobsberg, Sweden" insert separately the following:

- [73] Assignee: .5. Philips Corporation, New York NewYork Signed andsealed this 1st day of October 1974.

p (SEAL) Attest:

MCCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer A Commissioner ofPatents

1. A printing appaRatus, comprising: a type drum having types arrangedaround a periphery thereof, said type drum mounted for both axialdisplacement and rotation; a printing hammer means movably disposedopposite said type drum, a printing sheet passing therebetween; and acord for displacing said drum and said printing hammer means so that thehammer means is set in a desired printing position along a printing lineof the printing sheet, and the drum is displaced relative to the hammermeans, said cord having a first portion supporting the hammer means, asecond portion supporting said drum, said first and second portionsextending along a printing line of said printing sheet, a third cordportion extending between one end of said first portion and a first endof said second portion, and a fourth portion extending between the otherends of said first and second portions so as to form a continuous cordsystem, a driving wheel engaging said cord and disposed on one end ofsaid cord system for moving said cord; and a pair of pulleys disposed onanother end of said cord system and engaging said cord, said pulleysbeing pivotably supported with respect to each and having a commonpivotable axis between them, said displacement of the drum relative tosaid hammer being achieved by pivoting said pulleys while locking thefirst cord portion supporting the hammer means against movement.
 2. Theprinting apparatus of claim 1, wherein said driving wheel is powered bya stepping motor, and said first portion of the cord supporting saidhammer means extends from one of the pair of pulleys to said drivingwheel.
 3. The printing apparatus of claim 1, wherein said pair ofpulleys are supported upon a pivotable support member, said pivotablesupport member being pivotably driven by a stepping motor which isgeared to said support.